COMPARISON OF RINGER'S ACETATE WITH 3% DEXTRAN 70 FOR VOLUME LOADING BEFORE EXTRADURAL CAESAREAN SECTION

We have studied haemodilution and cardiovascular responses toi.v. hydration with either 3% dextran 70 (Dx70) or Ringer'sacetate using a non-invasive cardiac output monitor (BoMed NCCOM3-R7)in 40 healthy parturients undergoing Caesarean section underextradural anaesthesia. Haemodilution was more pronounced, andcentral venous pressure, mean arterial pressure and cardiacindex maintained at greater values, after treatment with Dx70.Colloid osmotic pressures (COP) decreased by 1.7 mm Hg afterloading with 3% Dx70, and by 5.6 mm Hg in mothers treated withRinger's acetate (P < 0.001). The transthoracic fluid indexdecreased more after hydration with Ringer's acetate (P <0.001), indicating an increase in lung water. In spite of thesematernal changes, there were no differences in neonatal bioimpedanceor values of haemoglobin, PCV, albumin and COP in umbilicalcord blood, and only one case of respiratory distress. We concludethat colloids may be preferable to crystalloids for circulatorypreload for extradural Caesarean section, as greater haemodynamicstability was maintained and increases in lung water avoided.     

COLLOID (3% DEXTRAN 70) WITH OR WITHOUT EPHEDRINE INFUSION FOR CARDIOVASCULAR STABILITY DURING EXTRADURAL CAESAREAN SECTION

Using a non-invasive cardiac output monitor (Bo-Med NCCOM 3–R7J,we have compared cardiovascular responses, degree of haemodilutionand incidence of nausea during extradural Caesarean sectionin healthy non-labouring mothers given either ephedrine 17.5mgand3% Dextran 70 7.5ml kg^–1 before delivery (group A)or volume loading with Dextran 15 ml kg^–1 without infusionof ephedrine (group B). Smallest systolic arterial pressuresbefore delivery were 114 (SEM 4) mm Hg (group A) and 105 (5)(group B). There were no significant differences between thegroups in mean arterial pressure, heart rate, systemic vascularresistance or central venous pressure, while cardiac outputincreased more with the ephedrine infusion (P < 0.05). Haemodilutionwas 8% in group A and 16% in group B at the time of delivery.Ephedrine infusion was associated with a smaller incidence ofnausea (P < 0.01). Umbilical arterial pH values were notdifferent between the two groups. We conclude that infusionof ephedrine, combined with low volume colloid administration,is a safe alternative to more extensive colloid volume expansionfor control of hypotension and provides effective prophylaxisagainst nausea during extradural Caesarean section in healthynon-labouring mothers.     

Biological evaluation of root canal antiseptics using in vitro and in vivo methods

Abstract – Five antiseptics commonly used in endodontic treatment were evaluated with regard to cytotoxicity and initial tissue irritating effect. The cytotoxicity was evaluated in a cell culture system using HeLa cells and the initial tissue irritating effect was assessed by application of the antiseptics onto an intact nonepithelialized tissue surface. The cell response was assessed by registering changes in the DNA synthesis of the cells and the tissue response was assessed by registering changes in the oxidoreductase enzyme activity of the tissue. To evaluate the ability of the cells and the tissue to overcome an induced damage, one part of the study included a recovery period before the condition of the cells and the tissue was assessed. The most severe cell and tissue reactions were caused by 5% Chloramine-T® whereas no differences in toxicity or tissue irritating effect were found between 0.04% Jodopax®, 0.1% Bioscpt®, 0.1 % Hibitanc®, or 0.5% sodium hypochlorite. The HeLa cells showed the best recovery after having been influenced by Jodopax, Chloramine-T or sodium hypochlorite solutions, whereas the best tissue recovery was observed in the experiments with Biosept and Hibitane.     

Biologic effect of polyisobutylene on HeLa cells and on subcutaneous tissue in guinea pigs

ABSTRACT – Polyisobutylenc (Oppanol B®) is a resin which may possibly have physical properties that make it suitable as a root filling material. The biologic compatibility of the material was assessed in in vitro (cell culture) and in vivo (subcutaneous implantation) tests. Oppanol B compounds of low molecular weights caused no cell damage in the in vitro tests. The results of the in vivo experiments indicated that Oppanol B was at least as well tolerated by the tissue as the conventional root filling materials, guttapercha and AH26®.     

Biologic effect of poiyisobutylene on bony tissue in guinea pigs

ABSTRACT – Polyisobutylene (Oppanol B®) is an adhesive resin which may be suitable in endodontics. The reaction of bony tissue to Oppanol B was assessed by implanting the material into the mandible of guinea pigs. The results indicated that Oppanol B was well tolerated by bony tissue and showed a better tissue compatibility than the root filling malerial AH26®.     

Cytotoxicity of corroded and non-corroded dental silver amalgams

The cytotoxicity of one conventional and four non-γ₂-amalgams was studied in a cell culture system, using the Millipore filter method. Before testing set amalgam specimens were kept in distilled water or in artificial saliva at pH 4, 5 or 7 for up to 28 wk to produce a corrosion layer on the test surface. Non-corroded set amalgam specimens were also tested. None of the non-corroded, set amalgams showed any sign of surface accumulation of cytotoxic products whereas the corroded amalgams showed varying degrees of cytotoxicity. Generally, the non-γ₂-amalgams gave a more pronounced cytotoxic effect than the conventional amalgam. When the corrosion procedure was carried out at pH 7, the various non-γ₂-amalgams showed different degrees of cytotoxicity. It appears that the difference in cytotoxic effect between the non-γ₂-amalgams and the conventional amalgam as well as the differences among the various non-γ₂-amalgams could be related to variation in the retention of corrosion products deposited on the amalgam surface.     

Splenic Erythroclasia: An Electron Microscopic Study of Hemoglobin H Disease

This is an electron microscopic study of the spleen in a case of hemoglobinH disease. The patient showed evidence in the peripheral blood of markederythrocyte fragmentation.

The spleen acted upon the abnormal erythrocytes in two major ways:

1. The erythrocytes entered the sinus lumen simultaneously via two intercellular slits on opposite sides of a lining cell and then split into twosphered fragments (which lay free in the sinus lumen) and the long,thin connecting fragment (which was retained in the cordal compartment and phagocytized).

2. Small, dense, spherical portions of erythrocytes were retained in thecord while the major portion of the cell was released into the sinus lumen. This is suggestive of pitting of rigid intracellular precipitates.

The erythrocytes emerged from their passage through the cords and maintained bizarre forms in the sinus lumen. It is possible that the contents of thesecells may be partially gelated to account for this.¹¹ This gelation is thought tolargely underlie their behavior in their circulation through the spleen. Evidence of increased erythrocytic breakdown was found in the numerous largemacrophages present in the cords.

Submitted on August 4, 1967 Accepted on November 1, 1967